Drop successful SSLv3 connections using IPtables

PoodleIptables

# Matching 'SSL SERVER HELLO' packets using IPtables
# Using some connection tracking to make sure not 
# to match randomly in the middle of some huge SSL 
# session. 

iptables --insert INPUT -p tcp --sport 443 \
  -m connbytes --connbytes-mode bytes --connbytes-dir both --connbytes 0:500 \
  -m state --state ESTABLISHED \
  -m length --length 46:375 \
  -m u32 --u32 "\
      0>>22&0x3C@ 12>>26&0x3C@ 0&0xFFFFFF00=0x16030000 && \
      0>>22&0x3C@ 12>>26&0x3C@ 4&0x00FF0000=0x00020000 && \
      0>>22&0x3C@ 12>>26&0x3C@ 8&0x00FFFF00=0x00030000" \
  -j LOG --log-prefix "SSLv3 Server Hello Handshake"
  
# Results in log messages such as:

#SSLv3 Server Hello Handshake